Extension review usually takes somewhere between 2 and 10 business days, with recently it being closer to that 10 day mark as there has been TwitchCon Europe and a holiday by Twitch staff that could have lead to a backlog of reviews in the queue.
There’s nothing you can do at this time but be patient, and wait as they work through the queue of reviews.
Please be patient, the review team will reach out to you when they have reviewed your Extension. Even if it only took 1 week the first time, review times vary depending on how many other Extensions are in the review queue, there’s nothing you can do to speed it up.
The only point of contact you would have is firstname.lastname@example.org but they will likely tell you the same thing I have, that there’s a queue and your Extension will be reviewed when possible. Anything from staff holidays, unusually large queues, Extensions that require the review team to consult with Twitch Legal or other departments, can all substantially increase the review time.
The exact process by which Extensions are reviewed is not publicly disclosed, all we know is that there is a review queue and the review team will email you if there is an issue.